Methods for strengthening edges of laminated glass articles and laminated glass articles formed therefrom

• US 10,384,324 B2
• Filed: 02/02/2016
• Issued: 08/20/2019
• Est. Priority Date: 02/02/2015
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Shafrir, Shai Negev
• Primary Examiner(s): Chan, Sing P
• Application Number:
  US15/546,975
• Publication Number:
  US 20180001434A1
• Time in Patent Office: 1,295 Days
• Field of Search: 156247, 156249, 156250, 156267
• CPC Class Codes: B24B 29/005 using brushes
• CPC Class Codes: B24B 37/00 Lapping machines or devices; Accessories B24B3/00 takes precedence
• CPC Class Codes: B24B 9/10 of plate glass
• CPC Class Codes: B32B 17/06 comprising glass as the main or only constituent of a layer, next to another layer of a specific material
• CPC Class Codes: B32B 3/02 characterised by features of form at particular places, e.g. in edge regions non-uniform thickness B32B3/263
• CPC Class Codes: B32B 37/10 characterised by the pressing technique, e.g. using action of vacuum or fluid pressure
• CPC Class Codes: B32B 37/12 characterised by using adhesives
• CPC Class Codes: C03B 17/02 Forming molten glass coated with coloured layers; Forming molten glass of different compositions or layers; Forming molten glass comprising reinforcements or inserts
• CPC Class Codes: C03B 18/12 Making multilayer, coloured or armoured glass chemical aspects C03C
• CPC Class Codes: C03C 15/02 for making a smooth surface
• CPC Class Codes: C03C 19/00 Surface treatment of glass, not in the form of fibres or filaments, by mechanical means sand-blasting, grinding, or polishing glass B24
• CPC Class Codes: C03C 27/10 with the aid of adhesive specially adapted for that purpose
• CPC Class Codes: C03C 3/091 containing aluminium
• CPC Class Codes: C03C 3/093 containing zinc or zirconium
• CPC Class Codes: Y02P 40/57 Improving the yield, e-g- reduction of reject rates

Abstract

Methods for strengthening edges of a laminated glass article comprising a glass core layer positioned between a first glass clad layer and a second glass clad layer are disclosed. The methods may comprise polishing the cut edges of the laminated glass article with a slurry of polishing media applied to the edges of the laminated glass article with brushes. An edge strength of the laminated glass article is greater than or equal to about 400 MPa after polishing.

Claims

1. A method for strengthening an edge of a glass laminate article, the method comprising:

creating a stack having an edge profile, the creating comprising;

applying adhesive to a top surface of the first glass laminate article;

placing a second glass laminate article on the top surface of the first glass laminate article, wherein each glass laminate article comprises a glass core layer positioned between a first glass clad layer and a second glass clad layer; and

applying pressure to a top surface of the second glass laminate article to create a first segment of the stack, wherein the first and second glass laminate articles of the first segment of the stack are adhesively but releasably bound;

polishing the edge profile of the stack by delivering a loose abrasive material to the edge profile to create a polished stack; and

separating the polished stack into two or more polished glass laminate articles, wherein the edge of each polished glass laminate article has an average strength value of greater than or equal to 400 MPa.

2. The method of claim 1, wherein the loose abrasive material is delivered with a rotating brush.

3. The method of claim 2, wherein the rotating brush is circular and comprises nylon bristles.

4. The method of claim 1, wherein the loose abrasive material comprises a slurry comprising CeO₂ particulates having a density of about 1.3 g/cm³.

5. The method of claim 1, wherein the polishing the edge profile comprises removing a portion of the edge profile to a removal depth of about 0.05 mm.

6. The method of claim 5, wherein the removing a portion of the edge profile comprises a series of consecutive removal passes, wherein each pass removes from about 8 μ

m to about 10 μ

m of material.

7. The method of claim 1, further comprising grinding the edge profile of the stack before polishing the edge profile.

8. The method of claim 7, wherein a grinding spacing between adjacent laminated glass articles during the grinding step is less than a polishing spacing between adjacent laminated glass articles during the polishing step.

9. The method of claim 8, wherein the grinding spacing is 20 μ

m to 100 μ

m and the polishing spacing is 100 μ

m to 220 μ

m.

10. The method of claim 7, further comprising, separating the ground stack into two or more ground glass laminate articles and stacking the two or more ground glass laminate articles before polishing the edge profile.

11. The method of claim 7, wherein the edge profile of the stack is ground with at least a rough abrasive wheel having fixed abrasive particles and a fine abrasive wheel having fixed abrasive particles.

12. The method of claim 11, wherein the rough abrasive wheel is metal bonded and has fixed abrasive particles in the range of from about 240 grit to about 400 grit.

13. The method of claim 11, wherein the fine abrasive wheel is electroplated and has fixed abrasive particles in the range of from about 800 grit to about 1200 grit.

14. The method of claim 11, wherein the fine abrasive wheel is metal bonded and has fixed abrasive particles in the range of from about 500 grit to about 800 grit.

15. The method of claim 11, wherein the fine abrasive wheel is resin bonded and has fixed abrasive particles in the range of from about 500 grit to about 3000 grit.

16. The method of claim 1, wherein the creating further comprises:

removing excess adhesive from the edge profile of the stack;

adjusting and aligning the edge profile of the stack; and

repeating the creating a segment of a stack steps to create one or more additional segments of the stack, wherein each segment of the stack is adhesively but releasably bound to at least another segment of the stack.